1-alkyl-2-hetero-1, 2, 3, 4-tetrahydro-quinazoline-4-ones



6,162,666 ice Patented Dec. 22, 1964 3,162,636 l-ALKYL-Z-HETERO-1,2,3,4-TETRAHYDRO- QUlNAZOLINE-4-ONES Harvey Gurien, Newark, N.J., and Thomas P. Gordon, Carnegie, Pa, assignors to S. B. Penick & Company,

New York, N.Y., a corporation of Delaware No Drawing. Filed Jan. 23, 1963, Ser. No. 253,294 4- Claims. (Cl. 260-251) where R is alkyl and R" aryl and methods for preparing. A related compound, l-methyl-Z-benzyl-1,2,3,4- tetrahydroquinazoline-bones has been reported as a degradation product from materials isolated from natural sources (Chakravarti et al., J. Chem. Soc., 1953, 33-37-40).

This invention according to its process aspects contemplates the reaction of the appropriate o-alkylaminobenzamide with the appropriate aromatic aldehyde according A suitable slightly polar solvent is a convenient medium for carrying out this reaction. For reasons of economy and solubility, the lower alkanols are the preferred solvents with ethanol as the solvent of choice. The reaction is encouraged by the presence of mineral acids. The mineral acids serve as sources of hydrogen ions. While phosphoric and sulfuric acid will encourage the reaction, hydrochloric acid is preferred as it is easily volatilized when the reaction is completed.

C ONHg It is preferred to carry out this reaction at the reflux temperatures of the solvents. Under such conditions, the reactions are completed at yields above within 24-36 hours.

The compounds of this invention have shown miticidal activity and are useful in controlling such economic pests.

The compounds of this invention were tested against the 2-spotted spider mite (Tetranychus telarius) according to a method developed at Rutgers University. 7 One week old bean plants at the 2 leaf stage, each leaf 1 /2 inches long are dipped into emulsions or solutions of candidate materials. Each test plant is then infected with approximately 25 adult mites. Mortality counts are made one and three days after treatment. The com pound of Example 1 in replicate tests produced an average 93% mortality when applied in 0.05% solution. The other compounds of this invention similarly showed miticidal activity.

The invention and its practice will be described in the examples below and is defined in the claims appended.

EXAMPLE 1 1-n-Pentyl-2-Phenyl-1,2,3,4-Tetrahydr0quinaz0line-4- Ones o-N, (l-pentyl) aminobenzamide (0.04 mole) 7.9 grams and (0.04 mole) 5.3 grams of benzylaldehyde are suspended in 30 to 40 ml. of ethanol, acidified with 1 drop of concentrated hydrochloric acid. The mixture is refluxed for 36 hours. The acidified solvent i removed under reduced pressure and the residue is recrystallized from toluene. The physical constants and analysis will be found in Table 1.

Examples 2 to 11 are prepared according to the method set forth in Example 1 using the appropriate o-N,(alkyl)- aminobenzamide and a slight excess of the appropriate aromatic aldehyde. The reaction medium and reaction conditions are substantially the same. The products of each of these examples are appropriately identified and their physical constants and analyses disclosed in Table 1 below. Appropriate changes in the reaction conditions and recovery procedures may be made in a manner normally employed by these possessing the usual skill of this art. By appropriate changes in the starting materials beyond those disclosed but within the scope of the disclosure other compounds within the scope of this invention may also be prepared and are deemed included within the ambit of this invention.

TABLE 1.2-SUBSTITUTED-1-ALKYL-1,2,3,4-TETRAHYDROQUINAZOLINE-t-ONES Analysis Com Yield, M.P., O.

No. R R percent (eoriz) Formula Calculated Found N S N S tuncorr.) 53. 2 150. 5-151. 0 49. 0 120. 121 48. 9 146-148 72. 5 141-143. 5 52. 2 122-125 85.8 111-112. 5 n-Pentyl 85. 5 12s. 4-126 CmHzzNzO a s We claim: 3. l-n-propyl-Z(2-fury1)-1,2,3,4-tetrahydroquinazoline- 1. A compound of the formula: 4-one.

4. 1-rnethyl-2(2-thienyl)-1,2,3,4-tetrahydroquinazoline- I 4-one.

(DH-R" 5 References Cited in the file of this patent /NH UNITED STATES PATENTS I I 2,408,633 Guenther et a1. Oct. 1, 1946 0 OTHER REFERENCES Where R is lower alkyl and R is a heterocyclic radical 1O Bohme et' a1.: Arch. Pharm., vol. 293 (1960), pages chosen from the group consisting of furyl, indolyl and 1011-20.

thienyl. Gut et a1: Chemical Abstracts, vol. 54 (1960), col. 2 1-rnethy1-2(3-indolyl)1,2,3,4-tetrahydr0quinazolin 4611 (ab. of Col]. Czechoslov Chem. Communs., vol. 24

4-one. 15 1959 pp. 3154-62). 

1. A COMPOUND OF THE FORMULA: 